Sounds like to me that you burned out your dimmer switch. You can't wire up the head unit with the orange wire. It will pop your dimmer switch. I had the same thing happen in my truck. I had my head unit installed, everything was fine for about 2 weeks. Then I tried to adjust my dimmer switch, and all the dash lights went out. Except my A/C cluster. When I removed the dimmer switch, the lights in the instrument cluster would work with lights. But then the A/C cluster would go dark. I replaced the dimmer switch, and everything is back to good.

That is where I would start, disconnect the dimmer/illumination wires, and try disconnecting your dimmer switch. If the cluster lights work, their's your problem. Hope this helps.

The orange/white wire from the pioneer unit needs to be connected to the solid orange wire on the metra harness. Cap off the orange/white and orange/black wires on the metra harness. Do not connect them to anything. This will make the radio automatically dim to a preset level when you turn on your parking lights or headlights. If you connect anything to the dimmer circuits you will start popping fuses or frying your dimmer switch.

Thanks for the feedback. I took everything apart and made sure that the wires properly connected. On the pioneer harness there is no orange wire. I think my mistake was that I put the Orange/White & Orange/Black together. I read on other threads and forums that if I do that I will definitely blow out the dimmer switch. Well today I separate the Orange/White & Orange/Black whenever I did that I had no dash light. But if I grounded the Orange/Black I would get dash lights. Now my lights on the AC Cluster (the knobs) went out. But I do get dash lights when I turn on the lights. So before I blow any major things on my truck I figure I'll try getting some feedback from you guys. As far as the dimmer or the ac cluster lights working I am not upset about. Of course I would like to have them work.

So what can I do?

Should I leave the Orange/White wire cap off and the Orange/Black wire grounded?

Or should both be cap off?

How much does the dimmer switch cost? is it original Toyota part or aftermarket?

Should I ground the Orange/Black wire and replace the dimmer switch?

Sorry for all the questions. In the several threads and forums I researched in I was not able to get a clear solution to restoring everything back to normal. If you found yourself in this situation how did you get things working back to normal, I mean where my dashboard lights work during the day & night, the dimmer function works, and my ac cluster works too?

If the pioneer radio has no orange wire at all, do not connect the orange wires on the metra harness to anything. Cap them all off. It sounds to me like you fried your dimmer switch because connecting those wires together on the harness basically created a short right to ground in the dimmer circuit. If you haven't checked your fuses yet, do that. But before you do anything make sure that those orange wires are disconnected and capped off. I'm willing to bet though that you will need a new dimmer switch. When I was an installer I saw people do this all the time lol